US Bridges

US 31 SB over Mangun Arm Ditch

Good

Marshall County, Indiana · 01.19 N US 6 · Structure no. 079794

Built
2014
11 years old
Condition
Good
inspected January 2023
Type
Tee Beam
Prestressed Concrete
Length
77 ft
1 main span
Daily traffic
638
2021 count
Owner
State
State Highway Agency

About this bridge

US 31 SB over Mangun Arm Ditch is a prestressed concrete tee beam carrying US 31 SB over Mangun Arm Ditch in Marshall County, Indiana. It was built in 2014, so it is 11 years old, younger than the Indiana average of 46.6 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 638 vehicles a day, roughly 23% of them trucks, projected to reach 15,568 by 2035. The structure is 77 ft (23.4 m) long and 46 ft wide. If it were closed, the detour would be 0.6 mi (1 km).

CarriesUS 31 SB
CrossesMangun Arm Ditch
Location01.19 N US 6
RouteU.S. Route 31
StateIndiana
Coordinates41.4665, -86.2878
Functional classRural Principal Arterial - Other

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure8 Very GoodNo problems noted.
Channel and channel protection9 ExcellentNo problems noted.
Last inspectionJanuary 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation7: Better than present minimum criteria
Deck geometry9: Superior to present desirable criteria
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating59 US tons
Inventory rating42.5 US tons

Structure

Structure typeTee Beam
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadHL 93
Structure length77 ft (23.4 m)
Longest span75 ft (22.8 m)
Deck width46 ft (14.1 m)
Roadway width43 ft (13.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic638 (2021)
Projected traffic15,568 by 2035
Trucks23%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesWaterway
Detour if closed0.6 mi (1 km)
TollOn a free road
National Highway SystemYes

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was US 31 SB over Mangun Arm Ditch built?

It was built in 2014, making it 11 years old in 2025.

What condition is US 31 SB over Mangun Arm Ditch in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in January 2023.

How much traffic does US 31 SB over Mangun Arm Ditch carry?

About 638 vehicles per day (2021 count), of which roughly 23% are trucks.

How long is US 31 SB over Mangun Arm Ditch?

The structure is 77 ft (23.4 m) long with a longest span of 75 ft (22.8 m) and a deck 46 ft wide.

Who owns US 31 SB over Mangun Arm Ditch?

It is owned by the State Highway Agency.